Overview
Aspirin and extended-release dipyridamole is a combination antiplatelet therapy indicated to reduce the risk of stroke in patients with prior transient ischemic attack (TIA) or completed ischemic stroke due to thrombosis. It works through dual mechanisms of platelet inhibition to prevent thrombotic events. The combination is not interchangeable with individual aspirin or dipyridamole components.
Mechanism of Action
Dipyridamole inhibits platelet aggregation by increasing intracellular cyclic adenosine monophosphate (cAMP) through inhibition of phosphodiesterase and blocking adenosine uptake. Aspirin irreversibly inhibits cyclooxygenase-1 (COX-1), reducing thromboxane A2 production and platelet aggregation. The combination provides dual antiplatelet effects through complementary pathways.
Indications
- Reduce risk of stroke in patients with prior TIA or completed ischemic stroke due to thrombosis
Common Doses
- 25 mg dipyridamole/200 mg aspirin extended-release capsule
Dosage
One capsule orally twice daily (morning and evening). Swallow whole without chewing. May be taken with or without food. For intolerable headaches during initial treatment, consider one capsule at bedtime with low-dose aspirin in the morning, returning to usual regimen within one week.
Contraindications
- Hypersensitivity to any product components
- Allergy to NSAIDs
- Asthma, rhinitis, and nasal polyps syndrome
- Children/teenagers with viral infections (Reye syndrome risk)
Side Effects
- Headache (most common)
- Gastrointestinal: dyspepsia, nausea, abdominal pain, vomiting, GI bleeding
- Cardiovascular: chest pain, angina, hypotension
- Neurological: dizziness, cerebral edema
- Hematologic: bleeding, bruising, thrombocytopenia
- Hepatic: hepatitis, hepatic failure
- Hypersensitivity reactions including anaphylaxis
- Renal: interstitial nephritis, proteinuria
- Dermatologic: rash, Stevens-Johnson syndrome
Interactions
- Anticoagulants/antiplatelets: increased bleeding risk
- NSAIDs: increased bleeding and renal impairment
- Adenosine: increased plasma levels and effects
- ACE inhibitors: diminished hypotensive effects
- Methotrexate: reduced clearance leading to toxicity
- Diuretics: diminished effectiveness
- Oral hypoglycemics: increased hypoglycemic effects
- Uricosuric agents: diminished uricosuric action
Counseling Points
- Take exactly as prescribed, usually twice daily
- Swallow capsule whole - do not crush or chew
- Report any signs of bleeding (unusual bruising, blood in stool/urine)
- Inform healthcare providers of all medications before starting
- Avoid alcohol consumption while taking this medication
- Report severe headaches, chest pain, or dizziness
- Seek immediate medical attention for allergic reactions